(grammar) (of a clause, conjunction, form of a verb, or whole sentence) expressing a condition on which something else is contingent: "If he comes" is a conditional clause in the sentence "If he comes I shall go"
(of an equation or inequality) true for only certain values of the variable: x² –1 = x + 1 is a conditional equation, only true for x = 2 or –1
(of an infinite series) divergent when the absolute values of the terms are considered
(logic) Also hypothetical. (of a proposition) consisting of two component propositions associated by the words if…then so that the proposition is false only when the antecedent is true and the consequent false. Usually written: p→q or p⊃q, where p is the antecedent, q the consequent, and → or ⊃ symbolizes implies